1. Field of the Invention
The present invention relates to techniques for regulating the temperature in computer systems. More specifically, the present invention relates to techniques for regulating temperature in computer systems by adjusting an iris opening(s) of one or more fluid ports.
2. Related Art
As semiconductor integration densities within computer systems continue to increase at an exponential rate, thermal dissipation problems are becoming increasingly problematic. In particular, as the operating temperatures of chip packages become higher, thermal cycling effects can begin to adversely affect the reliability of computer-system components. A number of degradation mechanisms are accelerated by thermal cycling at high temperatures, including: accelerated solder fatigue, interconnect fretting, differential thermal expansion between bonded materials, delamination failures, thermal mismatches between mating surfaces, differentials in the coefficients of thermal expansion between materials used in chip packages, wirebond shear and flexure fatigue, passivation cracking, electromigration failures, electrolytic corrosion, thermomigration failures, crack initiation and propagation, delamination between chip dies and molding compounds, delamination between the molding compound and the leadframe, die de-adhesion fatigue, repeated stress reversals in brackets leading to dislocations, cracks and eventual mechanical failures, and/or deterioration of connectors through elastomeric stress relaxation in polymers.
These problems can be addressed by reducing the thermal cycling associated with customer workload variations using existing techniques, such as ‘chip throttling’ and/or ‘trash burning.’ During chip throttling, chip temperatures are reduced by decreasing processor clock frequencies when customer workloads are high. Similarly, during trash burning, chip temperatures are increased by increasing processor activity when customer workloads are low.
However, when chip throttling is activated, the computer-system throughput is reduced when a customer application needs it the most (i.e., when customer workload is high). Moreover, this can create a so-called ‘snowball’ effect because, when application demand is high, throughput slows down, which can cause application demand to pile up, which can cause throughput to slow down even further. Additionally, trash burning increases the power consumption of the computer system without performing useful additional computations, which wastes energy and usually results in a needless increase in greenhouse gas emissions from a power plant.
Hence, what is needed is a technique for controlling temperature variations in a computer system without the above-described problems.